Once you have created lun , now the next thing is how do you want to connect to that lun , is it FC or ISCSI , if it is ISCSI and assuming you have windows 2003 you need to do the following
* Add the controller IP in the Microsoft ISCSI initiator and login
* On the controller create a igroup and add the iqn id of the host to this igroup.
* Map the lun created to the igroup
* Once mapped go to My Computer--->Manage--->Disk Management and rescan the disks
If the above steps have been done properly you will see the lun as one of the disk which can be formatted and is ready to use. For FC we will have to create Igroup with the host WWN and map the lun to that igroup.